Heat 3 tablespoons of oil in a pan add the courgettes and fry till brown. Season with salt and pepper. Heat another tablespoon of oil and saute the spring onions. Keep one tablespoon of chopped spring onions back for garnish.
Place the tomatoes on the vine in an ovenproof dish. Drizzle with one tablespoon of oil and bake it for 10-12 minutes until they start to burst. Season with salt and pepper.
Whisk eggs with salt and pepper and add the courgettes and the spring onions. Heat one tablespoon of oil in a pan (ovenproof handle), place the egg mix in the pan and fry it for 3 minutes. Place the pan in the oven and bake the tortilla for 5 to 7 minutes. Place the tortilla on a plate and slice it. Top it with the remaining chopped spring onions. Serve with the roast tomatoes.